Dobby loom and method of weaving



Dec. 20, 1955 A. WIDMER 2,727,538

DOBBY LOOM AND METHOD OF WEAVING Filed April 10, 1951 4 Sheets-Sheet l Im Ado/f W/am kWh Dec. 20, 1955 A. WIDMER 2,727,538 BOBBY LOOM AND METHOD OF WEAVING Filed April 10, 1951 4 Sheets-Sheet In van far Ado/f Vlfidmcl Dec. 20, 1955 A. WIDMER 2,727,538

DOBBY LOOM AND METHOD OF WEAVING Filed April 10 1951 4 Sheets-Sheet 4 I'M 5770K Ado/ 011. Ufa Mel!" Arrow fr Unitid Stews atent-O 2,727,538 DOBBY LOOM AND METHOD OF WEAVING Adolf Widmer, Horgen, Switzerland, assignor to Gebr. Sti'iubli & Co., Horgen, Switzerland For the production of the simplest fabrics, those woven in tatfeta (plain), each half of the warp threads are brought one after the other into the top or bottom shed for each pick; that is to say for each pick one half of the threads is in the top-shed, the other in the bottom-shed and at the moment of beating-up the threads change their position, i. e. those of the bottom-shed are brought into the top-shed and vice-versa. The improvements according to this invention do. not relate to such simple tatfeta weaves, but to all others having combined patterns, i. e. woven fabrics which, for example, have both taffeta as well as satin bindings.

For the production of fabrics with combined weaves the warp threads will be moved according to the pattern, that is one part of the threads has to be in the top-shed during the passage of the shuttle, the other in the bottomshed and after each pick the threads have either to change from the top-shed to the bottom-shed or partly remain in the top-shed and those from the bottom-shed have to change to the top-shed or partly remain in the bottomshed for the following pick. In one known method for weaving of this kind all the warp threads are at the moment of the beating-up in the middle-shed; those threads, which for the next pick have to go from the top-shed into the bottom-shed, will be brought out of this position into the bottom-shed and those which have to be in the top-shed for the next pick return from the middle-shed into the topshed. In like manner is the movement of those threads which were brought from the bottom-shed to the middle shed and from there one part is brought to the top-shed and the other returns to the bottom-shed, the technical term for this weaving is weaving with closed-shed. In another well known weaving method only those threads will be moved which for the next pick change from thetopshed to the bottom-shed and vice-versa, while those threads which for the next pick have to stay in the top or bottom-shed will not be moved, but will be kept in their positions. At the moment of the heating-up only a few threads are in the middle-shed, while all the others are in the top or bottom-shed, the technical term in this case is open-shed.

Since in the weaving method with .closed-shedi at the moment of the beating-up, that is when the previous pick will be beaten up by the reed, all warp threads are in the middle-shed, that is to say they are all on the same level, the beating-up of the pick will be more ditficult, because it is squeezed by all the warp-threads. In the weaving method with open-shed the beating-up is easier because some of the warp threads are in the top-shed and some are in the bottom-shed; but these warp threadshave a much stronger tension than those which are in the middleshed, which are almost without tension.

One as well as the other of these methods operates disadvantageously for the fabrics and it is the aim of this invention to create a weaving method which avoids these disadvantages.

. drance.

In this novel weaving method the warp threads will be moved in such a way that at the moment of the beating-up neither all of the warp threads are in the middle-shed (closed-shed) nor a part of them will be in the middleshed and the others in the bottomand top-shed (openshed), but all warp threads will be moved in such a way that at the moment of the beating-up those warp threads which for the next pick have to change from the topto the bottom-shed and vice-versa, are in the middle-shed and from there'continue their movements; and those warp threads, which for the next pick again have to be in their previous positions, that is in the top or bottom-shed, are brought at the moment of the beating-up into a position which is between the topand middleor bottomand middle-shed and from there return again to their previous positions, that means to the topor bottom-shed.

This method unites the advantages of the closed-shed dobby, that is the rather equal tension of the warp-threads at the moment of the beating-up with the advantage of the open-shed dobby, that is the graduated position of the warp threads at the moment of the beating-up without having the typical'disadvantages of both known methods.

In the accompanying drawings two constructional examples of the machines, by which this new weaving method can be accomplished, are shown schematically:

Figure 1 shows an apparatus by which the movement of the harness-frames are accomplished by cams through a treadle motion.

Figure 2 shows the cam itself on an enlarged scale.

Figures 3-7 show execution of the apparatus as a dobby for the movement of the harness-frames.

Figure 8 shows a diagram of time and course for the apparatus according to Figures 3-7.

Figure 9 is a side elevational view of a portion of the machine in accordance with the invention showing the mechanism for moving the knives.

Figure 10 is a top plan view of the arrangement shown in Figure 9.

The arrangement of the treadle motion at the side or above the loom and the drive of the shaft 6 are known, the cam 7 being fixed on the shaft 6. In the groove 8 of the cam 7 moves a roller 10 which is fixed on a double armed lever 9, mounted oscillatingly on a stationary shaft 11. A connection rod 13 is hooked to the upper end of the double lever 9 and is connected with jack-levers 14, thus transmitting the motion of the double-armed lever 9 in well known manner to the jack levers 14 and 15 on which a harness-frame 16 is suspended. The whole apparatus is shown in the position where the harness-frame tion, so that the shuttle can pass' through the shed without being hindered. It is to be understood that a turn of degrees of the cam corresponds with a Whole turn of the crankshaft of the loom. At the beating-up, corresponding to a turn of the crankshaft of the cam 7 has turned 45. The roller 10 is now in position 2 of the cam 7 and the upper end 12 of the double lever 9 has moved accordingly from 1 to 2 so that the harnessframe 16 moved down from position 1" to 2". The sudden change by the beating-up will meet now those warp threads drawn in this harness-frame 16 at a tension which almost corresponds with that of those warp threads which are in the middle-shed.

At a further turn of the cam 7, the groove 8 acts through the roller 10 and the levers 9, 14 and 15 on the harness-frame 16 and moves this again to the topshed position 1' and the shuttle can pass without hin- The next quarter of a turn of the cam 7, corresponding to afurther turn of the crankshaft of the loom,

cam 7 to position 4, thus moves the harness-frame 16 in well known manner into the bottom-shed position""by passing through the position 3" which means the middle-shed position at the moment of the beating-up.

While with the execution of cams known hitherto the groove 8 stays ona radialcourse for the furthervqnarter turn and keeps therefore the harness-frame 16 in'the bottom-shedposition 5., the'roller .10 .according to'the present invention 'will bebrought fromposition5 ofthe moving 'the harness-frame .16 at the moment of the beating-up into position 4 and then letting the lever down again into the bottom-shed position 5" for the next pick.

The apparatus shown in Figures 3-7 for the execution of the new weaving method is a dobby, theworking principle of whichis known. .A lever 18 is n'iounted rockingly on a stationaryshaft 17 and carries at 19 a baulk lever 20 on which are mounted movably at both its ends 20 and 20" hooks 21 and=22 respectively. it according to the pattern card a harness-frame has to be brought to the bottom-shed or to the top-shed the hook 21 will be hooked on knife 23 or 24 respectively and similarly the hook 22 will be hooked on knife 25 or 26 respectively. Figure 3 shows the pattern card 37 with wooden lags and pegs the pattern card the harness-frame will be brought up to the top-shed, in other words the hook 21 will be hooked on the knife 24. If there is no peg on the card, the harness-frame will be brought to the bottom-shed and this example is shown in Figure 3 by the position of the hook 22 being hooked on the knife 25. It will be understood, of course, that there is a separate row of' pegs for each hook 21 and 22. The same will occur with a pattern of Verdol paper, i. e. a paper pattern card with an appropriate pattern reading device so that the rows of holes in the paper pattern will direct the hook 21 to be hooked on the knife 24 and accordingly the hook 22 to be hooked on the knife-26 and if there are no holes in the pattern card, the hooks 21 and 22 would be hooked on the knives '23 and 25 respectively. manner, the pattern will be indexed once each pick, with hook 21 being controlled on alternate picks and hook 22 being controlled on intervening picks.

Fig. 9 shows the manner in whichthe means for moving the knives 23, 24-, 25 and 26 are arranged in they dobby. Referring to Fig. 9, shaft 40 is rotatably mounted in a pair of frames 38 and 39 and this shaft carries on each side of the dobby adouble cam 41 and-42. A pair of levers 43, one on each side of the dobby, carry the knife 26 and are mounted on a pivot 44 on each dobby frame and each lever is provided with a roller 45 which engages in the outer groove46. of the cams and thus transmits a toand fro. movement .to knife.26. A similar arrangement is provided for knife .25 withthe movement of this knife being controlled by the inner groove 47 of the cams. Knife 23 is carried by the pair, of levers 48, one on each side ofthe dobby, each lever being mounted on a pivot 49 and being linkedby rods'50 to a pair of levers 51. Levers 51 are mountedon pivots 52 and are provided with rollers 53 which engage with the outer grooves 46 of the cams and a similar arrangement is provided for knife 24 whichtis controlled from'the inner groove 47 of the cams.

The plan view of Fig. 10 shows the manner in which a plurality of levers .18, baulk levers. 20, hooks 21 and 22 and a pattern card are mounted in a dobby. The cam shaft 46 carries at its end a bevel gear 55 which meshes with a bevel gear 56 mounted on the dobby driving shaft 57. The pattern cylinder isalso driven by worm 53 from the dobby driving shaft.

While in the. constructions of dobbies known hitherto these knives work either'on the principle of the doublelift-open shed at which all-the four knives transmit their movements to the hooks 21 and 22 atexactly the'same time, or withtheprin'ciple ofthe'closed shedatwhich' and whenever there is a peg on' In conventional the knives 23 and 24 work together with the hook 21, while the'knives'25 and 26 are with the hook 22 in the rest position and vice-versa, the knives according to the present invention work as shown by the diagram Figure 8. In this diagram the moment 27 corresponds with the position of the knives as shown in Figure 3, the lines 23', 24, 25, and 26 show the movements of the corresponding knives during two picks, that is during two turns of 360 of the crankshaft of the loom. At the moment 27 the knives 23 and 24 are fully pulled out with the hook 21 hooked on the knife 24, so that the harness-frame 16 will be kept in the top-shed by the levers 18, 14 and 15 as in Figure 1. At this moment, i. e. when the shuttle passes through the shed, the next pick will be read in well known manner for the hook 22 by the pattern 37. The two knives 25 and 26 still keep their rest position, when the knives 23 and24'start to work. Only at the moment 28 (Figure 8) will they start their movement after the hook 22 has been brought into the desired position according to the pattern 37. While between the moment 27 and 23 (Figure 8) the movement of the hook 21, which is hooked on the knife 24, causes at all events the lowering of the harness-frame 16, this lowering of the harness-frame will be accelerated or retarded by the hook 22-from' the moment'28 depending on whether the hook 22 has been hooked on the knife 25 or 26 respectively. If the latter has occurred, there results for the harness-frame 16 a movement according to line 33, of which the moment '29 corresponds with the moment of the beat-up (see Figure 4), the harness-frame 16 being in position 2" of Figure 1.

In the further course of operation Figure 5 corresponds with the position 30 of the diagram, Figure 6 with position'31 and Figure 7 with position 32 of the diagram. The

line 33 shows the movement of the harness-frame 16, when it has to be in the top-shed for two successive picks.

The line 34 shows the movement of the harness-frame when for two successive picks it has to be in the bottomshed. The line 35 shows the resulting movement of the harness-frame 16 from the top-shed to the bottom-shed and back again; the line 36 shows the contrary, that is to 'saywhere'the harness frame 16 has to rise from the bottom-shed to the top-shed and has to move down again to thebottom-shed. As an example Figures 3-7 show the position of the hooks 21 and 22 and the knives 23, 24, 25 and '26 during two successive picks with a movement of the harness-frame 16 which for the next pick, that means for the next opening of the shed according to the line 33 coming from the top-shed, has to return again to the-top-shed, see Figures 3, 4 and 5, and for the movement of this harness-frame during the next pick from the top-shed according to Figures 5, 6 and 7 corresponding to the line 36 will be brought to the bottom-shed. Figures 5, 6" and 7correspond with the moments 30, 31 and 32 of Figure 8.

-What'I claimis:

1. Ina dobby loom, means for moving a harness comprising a'lever rockably mounted upon a shaft, a baulk "lever carried by saidfirst-named lever, a hook pivotally mounted at each end of said baulk lever, knives positioned to be engaged with said hooks, said knives being adapted to move the harness and means for moving said knives at time-intervals which are offset and in overlapping relationship with each other such that the harness will be moved during an interval of two successive picks "selectively from the top-shed to the bottom-shed, from the bottom-shed to the top-shed, and selectively from the top-shed and the bottom-shed to a position between one of said' sheds andthe middle-shed and returned to the "shed'from" which it was moved.

2. A method of weaving in a dobby loom having a harness comprising. a lever rockably mounted upon a "shaft,'a baulk lever carried by said first-named lever, a hook pivotally mounted at each end of said baulk lever,

knives positioned to be engaged with said hooks, said knives being adapted to move the harness which comprises moving said knives at time-intervals which are offset and in overlapping relationship with each other References Cited in the file of this patent UNITED STATES PATENTS Cutler July 26, 1898 Staubli Aug. 6, 1901 Seckel Sept. 11, 1928 Staubli et a1. Apr. 21, 1953 FOREIGN PATENTS Switzerland Dec. 2, 1940 

